This invention relates generally to electromagnetic clutch/brake assemblies and deals more specifically with a configuration for such an assembly that utilizes a single electromagnetic coil to operate both the brake and the clutch, and that utilizes a single return spring to achieve return movement of the clutch and brake to a normal or non-energized condition.
The general purpose of the invention is to provide a clutch/brake assembly wherein engagement of the brake is achieved when the coil is deenergized and wherein the clutch is disengaged. More particularly, when the coil is energized, the clutch engages and the brake disengages, and conversely deenergizing the electromagnetic coil causes the brake to engage as the clutch disengages.
Prior art clutch assemblies of the type that have a single electromagnetic coil for operating both a clutch and brake are known, and typical such units are shown in U.S. Pat. Nos. 3,504,773 and 3,893,191. These prior art constructions depend upon deflection of a relatively weak spring acting between the clutch armature and an input hub, and a stronger spring acting on a brake armature to assure engagement of the clutch prior to release of the brake and vice versa. The present invention provides for separation of both clutch and brake with a single electromagnetic coil and single return spring.